The purpose of this study was to develop a valid and reliable instrument in order to measure the level of autonomy of Turkish classroom teachers. For this purpose, an 18-item 5-point Likert type scale was developed and tested. Data were collected from 292 classroom teachers (teaching at grades 1 to 4) working in state elementary schools located in five main districts of Ankara, and analyzed through Exploratory Factor Analysis (EFA) in order to investigate the factor structure of the instrument. EFA resulted in three factors named as (1) autonomy in instructional planning and implementation, (2) autonomy in professional development, and (3) autonomy in determining the framework of the curriculum. Also, Cronbach's Alpha coefficients were calculated for all subscales and the whole scale. The Cronbach's Alpha coefficients for the 1st, 2nd, and 3rd factors of the instrument were calculated as .91, .80, and .86 respectively, and the Cronbach's Alpha coefficient for the whole scale was calculated as .89. While the reliability of the 1st factor was considered as 'excellent', the reliability coefficients of the 2nd and 3rd factors, and the whole scale were considered as 'very good'. This study was the first step of an instrument development. Second step will be taken for the verification of the validity and reliability of the scale. (C) 2015 The Authors. Published by Elsevier Ltd.